After witnessing her father and perverse stepmother being killed by the cenobites, Kirsty Cotton is sent to a psychiatric institution. Despite her attempts to convince the authorities of what really happened to her family, no one believes her version of the story, and they decide to place her in the institution to rest and relax. The hospital is led by a brilliant and peculiar psychiatrist, Dr. Channard, who has long been searching for the key to another dimension. The only person who believes in Kirsty is a young and kind assistant to Dr. Channard, named Kyle MacRae. Following Kirsty's version of the story, Channard touches the bloodstained mattress where her stepmother Julia died. Channard decides to resurrect her by killing his patients and offering them as food for Julia. She returns without skin and decides to help Channard evoke the forces of evil. However, their plans are disrupted by Kirsty, who wants to end things with the cenobites once and for all, and by Kyle, who doesn't want to see Kirsty get hurt...